Non-volatile memory has been integrated into a wide range of electronic technologies, including cellular communication, digital video, digital audio, and compact data storage (i.e., flash memory cards, flash memory sticks, and USB flash drives). Silicon-oxide-nitride-oxide-silicon (SONOS) memory is a non-volatile semiconductor memory, at the heart of which is a transistor that can retain a value without a constant power supply.
A sidewall SONOS memory device includes a two dimensional array surrounded by a periphery region. The periphery region may include sidewall SONOS transistors in addition to other complementary metal oxide semiconductor (CMOS) logic and analog circuitry. Existing methods of manufacturing memory array sidewall SONOS transistors and peripheral sidewall SONOS transistors on the same die are complex, time consuming, and costly.
For example, a sequential method of manufacturing a sidewall SONOS memory device may include two sequential sets of steps. A first set of steps forms the sidewall SONOS transistors in the memory array and a second set of steps forms the circuitry in a periphery area on the same die. However, many of the steps in the first and second sets of steps may be the same or similar, and the inherent redundancy in the sequential manufacturing method results in lower production rates and lower revenue. Hence, there is a need for an integrated method of manufacturing sidewall SONOS and its periphery in a simple and logic-compatible process flow.